Question about resizing windows on startup

I'm dealing with an old system here at work that uses ratpoison for
the touchscreen UI. It worked fine on the 1024x768 monitors we used to
use, but we are having problems with newer 1280x1024 monitors - there
is a gray bar at the bottom of the screen that I can't seem to get rid
of.

Now, I'm calling Firefox in this window - is there something I can do
to force the window to go to 1280x1024?

Jim